1. Field of the Invention
This invention relates to a two-port solenoid valve that is adapted to open on momentary supply of current and remain in the opened position.
2. Description of the Prior Art
Some of self-holding type solenoid valves are opened by a momentary supply of current to an electric cally energizing coil and remain in the fully opened position after the current is switched off by means of a permanent magnet or the like. However, to open the valve, as with common solenoid valves, the solemoid must have a large enough capacity to pull the valve away from the valve seat into the fully opened position when current is supplied to the coil thereof. In this type of solenoid, however, the armature is in the remotest position from the fixed iron core when the valve is pulled away from the valve seat, the attraction force between armature and fixed iron core is very weak at this position in spite of the valve opening requiring the largest force. For this reason, the conventional solenoid valves of the above type are relatively large and costly.